Predictors of health-related quality of life and association with survival may identify colorectal cancer patients at high risk of poor prognosis

Purpose: To investigate the mediators of health-related quality of life (HR-QoL) in colorectal cancer (CRC) patients and effect on overall survival. Methods: We analyzed baseline (within 1 year of diagnosis) SF-12v1 questionnaire data from 3734 CRC patients and assessed the differences in mental composite scores (MCS) and physical composite scores (PCS) by socio-demographics and risks of poor HR-QoL by these factors. Hazard ratios were generated using univariate Cox regression for MCS and PCS dichotomized using the normalized scoring-based mean of 50 and survival estimates generated using the Kaplan–Meier method. Results: Differences in MCS and PCS were identified by sex, age, education level, alcohol use, tobacco use, and stage. Race, marital status, and cancer site differed only by PCS. Being female, never married, former alcohol user, or with stage IV disease significantly increased risk of a poor HR-QoL, with magnitudes of risk from 1.25- to 1.97-fold. Higher education level had a protective effect (MCS: P_trend = 2.32 × 10⁻⁷; PCS: P_trend = 5.62 × 10⁻¹⁴). Hispanics and African-Americans had a 1.35- and 1.57-fold risk of poor PCS, and increase in age had a protective effect for risk of poor MCS (P_trend = 1.84 × 10⁻⁷). Poor MCS or PCS were associated with poor prognosis and decreased survival at 5 years (HR_MCS 1.57, 95 % CI 1.41–1.76 and HR_PCS 2.38, 95 % CI 2.08–2.72), and both remained significant when adjusting for age, gender, race, education level, tumor stage, and tumor site. Conclusions: Our findings identify potential mediators for HR-QoL and suggest that baseline HR-QoL assessment may be prognostic for CRC.